Hey guys, i've been referred to this site by many a people, one of whom includes Moates. Basically... i'm the unloved step child of the Fbody world. I have the oh so lovely optispark with cast iron Lt1 yet, Eprom ecu management.

My problem is that all the people on Lt1tech.com have 94+'s and no one knows about Eprom. And then here, i'm not a 3rd gen so i will be unloved :P Moates recommended I get his $85 prom burner and then a $5 prom chip to flash. I have a moates memory adapter from when the previous owner had PCMForLess flash it for his nitrous specs.

My problem, is that i've taken off the nitrous and running it n/a. He put 42lb Ford Racing injectors on it, and im running pretty rich at WOT and my afr is messed up. Moates recommended I use "Tuner Pro" with the LT1_1992-93.ads file. My only concern, is through browsing the .ads file the cubic inches of the engine isnt 350ci, its like 248. So i'm very skeptical as to how much information pertains to the 1993 Lt1. He said you guys would probably be my best bet in answering any questions with Eprom management I've got tons more questions but i'll ask those later hehe

 

Ah, the nefarious "Baby LT1".....

You can still use the 92-93 binary as a starting point. Just correct the engine displacement numbers, get some smaller injectors (probably 19's or so), correct that value in the binary, and start datalogging.

And give me a holler if you need a replacement or spare block for that Baby. I've got one too many of those in my garage right now.

 

If you find TunerPro doesn't have your Calibration defined enough, there is also TunerCat which is has your calibration extensively defined.

Also, you just need to read your existing BIN and change the injector constants but you may find it best to go back to your original injectors as 42#s are quite large and you may find it too hard to fine tune - especially idle.

While this is a 3rd Gen site, we don't flat-out reject you just because you don't have a 3rd Gen application. However, please don't get upset if you don't get many responses as people tend to reply to applications they are familar with.

Wish I could type more, but I am on a quick break and have great difficulty typing right now.

 

You know of any other places I can get the Moates chip reader/writer? Or is the $85 deal from the site the best. I was thinking of just taking out the chip thats currently in there, reading it, and editing that. It should have the displacement and a lot of the timings in there.


Heh ya 22# vs 42# injectors are a big change. But if I define the current injectors to output as much as stock it should be just fine, theoretically correct?

Heh and I know i'm not the reject of the 3rd Gen world, I was just making a big statement of how unloved the 93 lt1's are

 

The problem with big "high-impedence" injectors, there is a minimium time the ECM needs to just open & shut the pintle. If injector is too large, the time gets too short and the pintle won't have enough time to open and squirt fuel.

The minimum amount of time the ECM needs to JUST open & close the pintle is around 0.9ms. If the ECM determines it needs less than 0.9ms - you get no fuel.

By using the proper injector size, the ECM will be able to calculate a long enough duration so the minimum amount of time is greater than 0.9 ms.

For large engines that need very large injectors, they have to look at low-impedence "P&H" injectors where the pintle can remain open and don't have to shut/close. But you probably need a different ECM with different drivers (as I am not very familiar with your specific ECM and whether it has the driver boards to handle 8 low-impedence P&H injectors.

 

if you are running stock displacement you might have to set your idle to 900-1000 to get a decent idle with those large injectors.. give us some engine specs. the moates $85 is about the best deal you will find for a flash chip programmer and a very simple to use software and interface. I would say if your current tune seems to work ok then read it and start from there or else donload a stock tune and adjust your injector constant and work on the VE table to get a perfect tune down.. lots of info here for SD tuning methods. sounds like you are on the right track

 

Heres some engine specs

-355ci
-cc305 cam
-Air foil (might get a 52mm or 58mm tb dunno yet)
-42 # Ford Racing injectors
-1.6 roller rocker arms

And then its all connected by SLP shorty headers. It's a nice solid lopey idle at like 830rpm but the major problem I have is at WOT I shoot a lot of black dust in peoples faces hehe Oh ya, and at a low gear if i'm trying to keep a solid speed like... 1st gear 20mph, I get some jerking and as soon as I let off the gas or put more, it smoothes out. Im guessing thats where the larger injectors + wrong AFR is causing it to do that.

 

Where are you located? You might find someone near you who can reburn your chip to lean it out.

 

Albuquerque - New Mexico

Everyone I know here in town has a 94 or up. We have a website kinda like this for the SouthWest area of a lot of car enthusiasts. But im the only 93 LT1 lol

 

Don't worry too much about the displacement and injector flows not being exact, sometimes the tuner needs to bias them a bit to gain headroom in the VE table.

Might also want to check out http://www.speeddensity.org/ since there are a fair number of folks that share your year/model over there.